When it comes to Neandertal diets, the consensus has been: they ate meat. Lots of meat. But now it looks like Neandertals chomped on a fair amount of veggies, too.

Researchers have had a tough time discerning the Neandertals’ diet. They evaluated carbon and nitrogen isotopes in bones, but those only correspond to some general kinds of proteins. Even plant remains in Neandertal teeth could have gotten there because a tasty animal carcass itself contained traces of a last vegetarian meal.

So the researchers relied on foolproof evidence—they studied Neandertal fecal remains from a site in southern Spain called El Salt. Neandertals made it their home about 50,000 years ago.

The researchers analyzed the samples for chemical compounds that can only result from metabolizing cholesterol from meat or from metabolizing plants. All five samples showed evidence of meat consumption. But two revealed the digestion of plants. Meaning that Neandertals did try vegetation, likely tubers and nuts. The study is in the journal PLoS ONE. Ainara Sistiaga et al, [The Neanderthal Meal: A New Perspective Using Faecal Biomarkers]

The scientists intend to use the same technique to examine soil samples at a 1.8 million-year-old site in Tanzania. In the hopes that any remaining poop may deliver an ancestral-diet scoop.